Communications networks such as the public Internet and private Intranets are becoming increasingly more accessible to individuals in both the home and office environments. Concomitant with the growth in Internet/Intranet services has been an increase in attempts to provide voice access between subscribers to the Internet as well as other computer-based networks.
In the context of full duplex voice communications over Internet/Intranet networks a multimedia personal computer equipped with a full duplexed sound card is required. In this configuration a sound blaster-compatible card, or equivalent, with an Internet telephone application running on the PC is normally used. This system does represent a new paradigm for voice communications but it does have several undesirable short comings. Since it relies on a sound-blaster compatible card in the personal computer it excludes the traditional telephone instrument. Because of the speaker-phone-like environment of the personal computer configuration a user of the system does not enjoy privacy in either transmission or receipt of voice messages. The system is also prone to inherent latency. There is also no fall back position should the Internet connection be lost or if the computers at either end of the conversation shut down.
The telephone adapter according to the present invention overcomes the aforementioned shortcomings in that it enables full duplex voice communication over Internet/Intranet networks using traditional telephone instruments. This, of course, provides improved privacy to the user. Additionally, the adapter interfaces with the public switched telephone network which allows the telephone to be used in its normal mode when the computer is turned off or otherwise disabled.
Briefly, therefore, the present invention enables traditional telephone instruments to be used for voice communications over IP networks. Users are not threatened with computer interfaces. Latencies due to operating system interfaces to sound cards are eliminated. Once the computer is turned off a path to the traditional telephone network is created.
The invention is applicable to the following technologies: a) voice over Internet/Intranet; b) telephony over the Internet/Intranet; c) PABX systems for Internet/Intranet; d) multimedia personal computers including Windows 95 and WindowsNT.
Therefore, in accordance with a first aspect of the present invention there is provided a system for use with a telephony terminal and a client to provide telephone access to a computer-based network via the client. The system comprises: means in the client to execute an operating system program; an adapter serially connected between the terminal and the client, the adapter having means to receive and transmit respectively telephony communications from and to the terminal; means to convert the telephony communications from analog to digital and digital to analog; and means to control transfer of converted telephone communications between the client and the adapter; and a system transfer protocol to coordinate transfer of telephony communications between the client and the adapter.
In accordance with a second aspect of the present invention there is provided an adapter for serial connection between a telephone terminal and a personal computer to provide telephony access to a communications network via the personal computer. The adapter has means to receive and digitize analog signals from the telephone terminal; means to receive digitized signals from the computer and to convert the digitized signals to analog form and means to transfer the signals between the computer and the telephone terminal.
In accordance with a third aspect of the present invention there is provided a method of transmitting voice communications over the Internet comprising: providing the voice communications via a telephone terminal to a serially-connected telephone adapter; digitizing the analog voice communications in the adapter; transferring the digitized signals to a serially-connected personal computer having access to the Internet; packetizing the digitized message and transporting the digitized signal to a selected destination in accordance with an operating program installed in the computer.
In accordance with a preferred embodiment of the method aspect, the voice message is received at the destination by a second computer wherein the signal in digital form is depacketized, transferred to the adapter whereat the digital signal is converted to analog form and subsequently provided to a second telephone terminal.